<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>404</title>
    <style>
        body{
            margin: 0;
            padding: 0;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
        }
    </style>
</head>
<body>
    <h2>404</h2>
    <h4>页面不存在</h4>
    <a href="javascript:;" onClick="javascript:history.back(-1);">返回上一页</a>
</body>
</html>